1. Field of the Invention
This invention relates to an unevenness inspection method, a method for manufacturing a display panel, and an unevenness inspection apparatus, and more particularly to an unevenness inspection method for inspecting the presence of unevenness in a panel material, a method for manufacturing a display panel using this unevenness inspection method, and an unevenness inspection apparatus for inspecting the presence of unevenness in a panel material.
2. Background Art
Conventionally, in manufacturing a liquid crystal display panel, the assembled panel is inspected for the presence of unevenness. The unevenness inspection is performed by sensory test based on visual observation by a human inspector, and hence presents a problem of high inspection cost.
In a recently proposed technique to solve this problem, a panel material under inspection is imaged by a camera, and a spatial differential filter is applied to the acquired image to automatically detect unevenness (e.g., JP 2003-066398A). However, in this conventional automatic inspection method, there is a problem of mismatch between the inspection result and the result of the inspector's sensory test, which hinders its practical application.